cryptic speaker selector instructions / impedance

Hello,
I am trying to drive 5 pairs of in-wall speakers from an Onkyo receiver using a 6-pair speaker selector (this one, if it matters: http://www.nextag.com/Pyle-PSPVC6-6-...60/prices-html)

The speaker selector manual says: "If you connect more than one pair of speakers, see 'impedance chart' on p. 6 to select the best terminals to connect. For best performance, make the connections based on how frequently you use each set of speakers." The chart on p. 6 shows impedance decreasing the more speakers are connected, which makes sense to me. What doesn't make sense is, the chart actually lists all the possible combinations of "on" speakers, A+B, A+C, A+D, B+C, etc. ... but still, for any given number of connected speakers, all possible combinations map to the same impedance.

So what is the manual trying to tell me? Does it matter what order I connect the speakers in, or doesn't it? I was going to connect them in descending order of frequency of use (from A always on, downward), just for intuition in using the buttons, but does it matter at all?

thanks in advance!

great, thanks, fair enough, 2 follow ups:
1. What's the benefit of the "protective circuitry" that my speaker selector claimed to offer, if I still have to worry about stressing the receiver? The speaker selector says it can play up to 6 pairs at once, is that just false advertising? [again, normal in-wall speakers, nothing fancy]

2. if I got a stand-alone amplifier, and put it between the receiver and the selector, would that help?

I kind of want to be able to play at least 4 pairs at once.
Thanks!

I don't have volume controls in each room, so I do need them on the unit. I saw "protective circuitry" in the description and I think I assumed that meant "impedance matching." Oops.
This one claims to have "selectable impedance magnification," would that have been what I needed? http://www.nilesaudio.com/product.ph...rdcdID=FG01044